The overall objectives of this project come under two general categories: 1) characterization of specialized membrane systems of procaryotic cells, and 2) characterization of the mechanism of gliding motility in certain procaryotic organisms. Most of our studies center around two organisms. A specialized membrane system is produced during part of the life cycle of Asticcacaulis biprosthecum (C-19) by an evagination of the plasma membrane and cell wall. Two of these structures (prosthecae) are produced from the lateral surfaces of each cell. An extensive internal system of membranes is produced by an invagination and proliferation of plasma membranes of cells of Cytophaga columnaris (1R43). Both of these specialized membrane systems can be purified, characterized, and their properties compared with the plasma membranes from which they wre derived. Our research is designed to answer the following questions: a) What are the functions of the specialized membranes? b) Are the specialized membranes differentiated biochemically with respect to the plasma membranes from which they are derived? c) If the membranes are functionally specialized, are there any properties of these membranes that would allow us to correlate structure to function? In addition, information concerning the function of prosthecae of A. biprosthecum will be useful in subsequent studies of the complex life cycle of this bacterium. C. columnaris (1R43) is the test organisms for our studies of gliding motility. Our long-term objectives here are to identify any structures responsible for this of motility, isolate and characterize any such structures, and compare this system with more highly evolved locomotory organelles in order to achieve a better understanding of the mechanisms of motility in living organisms.